1. Field of the Invention
This invention relates to flow control valves operable to bleed pressure from a pressurized source. More particularly, this invention relates to flow control bleed valves having a check valve incorporated therein allowing pressurization of the pressure source.
2. Description of the Background Art
Presently, there exist many types of flow control valves operable to regulate the flow of a fluid into and out of a tank or other container. Basically, the more predominate type of flow control valve comprises a spring-loaded ball which is urged against a valve seat by means of a vented turn knob. During operation, rotation of the turn knob increases (or decreases) the space between the ball and the valve seat, thereby regulating the flow of fluid therethrough. These types of flow control valves work quite suitably and reliably. However, since each component part of the flow control valve requires machining and deburring, these valves are manufactured at a relatively high cost.
In many applications, it is desirable to incorporate a check valve into the flow control valve such that the flow of fluid in one direction is uninhibited, while the flow of fluid in the opposite direction is controlled. For example, in the medical field, it is almost universal practice to utilize a flow control/check valve in-line between the pump bulb and the inflatable cuff of a blood pressure monitor (sphygmomanometer). The check valve of a control valve of this nature allows the inflatable cuff to be freely inflated to a desired pressure by pumping of the pump bulb. After the cuff is suitably inflated to the desired constricting pressure about the patient's arm, the cuff is slowly deflated by slowly bleeding the pressure contained therein through the use of the flow control valve. Of course, many other applications exist which require the use of a flow control valve having a check valve incorporated therein.
In regard to sphygmomanometers, there exists a need for a flow control valve having a preset bleed rate which allows the inflatable cuff to be bled at a preset, constant rate so that the inflatable cuff is not deflated too rapidly. The operator thus obtains an accurate systolic and diastolic pressure reading.
Therefore, it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the flow control valve art.
Another object of this invention is to provide a flow control valve which is economical to manufacture and highly reliable in operation.
Another object of this invention is to provide a flow control valve composed of injection molded parts which do not require machining or deburring prior to assembly thereby reducing the cost of manufacture thereof.
Another object of this invention is to provide a flow control valve having a turn knob which, on rotation, variably controls the flow of fluid therethrough.
Another object of this invention is to provide a flow control valve having a check valve incorporated therein, allowing a tank or other container to be inflated to a pressurized state by means of the check valve and then slowly deflated to a depressurized state by means of the variable flow control valve.
Another object of this invention is to provide a flow control valve operable as a bleed valve to bleed pressure from a pressurized source.
Another object of this invention is to provide a flow control valve having a turn knob, which, on rotation, controls the flow of fluid therethrough at a preset rate allowing the flow control valve to be utilized in conjunction with a sphygmomanometer to obtain systolic and diastolic pressure readings.
Another object of this invention is to provide a flow control valve having a turn knob which, upon rotation by approximately a quarter turn, controls the flow of fluid therethrough at a first preset rate, and then, upon further rotation of the turn knob, controls the flow of fluid therethrough at a second, higher rate.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.